| 摘要 |
PURPOSE:To efficiently transmit desired information by setting the irradiating position of a transmission light beam so that the center of a variation zone coincides with the center of a receiving lens, and setting the irradiation zone of the transmission light beam so that a zone wider than the variation zone by the portion of the radius of the receiving leans is irradiated. CONSTITUTION:When the center of the variation zone AR is irradiated by the transmission light beam LA1, an optical space transmission device 1 is adjusted so that the irradiation zone of the transmission light beam LA1 is circumscribed to the zone expanded from the variation zone AR by the portion of the radius (r) of the receiving lens. Namely, the amplitude AB in x-direction and y-direction of the variation zone AR is detected, and the coordinates (X0, Y0) of its center are detected. Further, deviation from coordinates (X0, Y0) to the center of the receiving lens 2 is detected, and the irradiating position of the transmission light beam LA1 held in the detecting state of the variation zone is changed by the portion of the deviation. Thus, the center of the variation zone AR and the center of the receiving lens 2 can be made to coincide with each other. |
